An invisible, non-toxic, easy to apply surface protectant that prevents the build-up of calcium and other mineral deposits on pool tile, glass and more. Protected surfaces are easier to maintain and most deposits are removed with light brushing or scrubbing. This eliminates the need for abrasive or acidic cleaners and keeps your surfaces looking new, longer. Use on a variety of hard surfaces including ceramic tile, porcelain tile, glass tile, natural stone, windows, shower doors, metal fixtures, mirrors, tubs and sinks. Dried product is safe for aquariums and marine life.